(19)
(11) EP 0 237 363 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
18.10.1989 Bulletin 1989/42

(43) Date of publication A2:
16.09.1987 Bulletin 1987/38

(21) Application number: 87302219.8

(22) Date of filing: 16.03.1987
(51) International Patent Classification (IPC)4: G01N 21/64, G01N 21/47
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 14.03.1986 AU 5040/86

(71) Applicants:
  • Norrish, Richard John
    Port Willunga South Australia (AU)
  • Wiskich, Joseph Tony
    Kensington Park South Australia (AU)
  • LUMINIS PTY. LIMITED
    Adelaide South Australia 5000 (AU)

(72) Inventors:
  • Norrish,Richard John
    Port Willunga,South Australia (AU)
  • Wiskich,Joseph Tony
    Kensington Park,South Australia (AU)

(74) Representative: Huntingford, David Ian et al
W.P. THOMPSON & CO. Coopers Building Church Street
Liverpool L1 3AB
Liverpool L1 3AB (GB)


(56) References cited: : 
   
       


    (54) Improvements in measurement of fluorescence


    (57) A fluorometer probe head and a method of operating a probe to overcome problems of reflectance, for example, for determination of chlorophyll in plant leaves, uses a red LED (6), whose radiation does not cause fluorescence in the sample, and a green LED (7), whose radiation causes fluorescence in the sample, consecutively directed to a particular target spot (5). A photodiode (8) records fluoresced and reflected signals and an accurate result is obtained by subtracting the reflectance obtained with the red LED (6) from the gross reflectance and fluorescence value obtained with the green LED (7), to give the fluorescence at the test point.







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